Effects of Sputtering Gas on Crystal Growth Orientations and Durability of Al-doped ZnO Transparent Electrodes in Harsh Environment

Aluminum-doped zinc oxide (AZO) transparent electrodes prepared by radio frequency (RF) magnetron sputtering were investigated to elucidate effects of crystal growth orientations on durability of AZO films, evaluated by electrical resistivity. During the deposition, the flow of oxygen gas was 60 sccm, while argon gas was varied from 3 to 60 sccm. As the argon gas flow increased, a transition of crystal growth orientations from (110) to (002) was observed by X-ray diffractometry (XRD). Damp heat test was conducted at 85°C and 85% of relative humidity for 25 days. As a result, the AZO films prepared with higher argon (or total) gas flows having (002) main crystal growth orientation exhibited better durability.